9.8 List various types of isomerism possible for coordination compounds, giving an example of each.
(a) Geometric isomerism:
This type of isomerism is common in heteroleptic complexes. It arises due to the different possible geometric arrangements of the ligands. For example:
(b) Optical isomerism:
This type of isomerism arises in chiral molecules. Isomers are mirror images of each other and are non-superimposable.
(c) Linkage isomerism: This type of isomerism is found in complexes that contain ambidentate ligands. For example:
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(d) Coordination isomerism:
This type of isomerism arises when the ligands are interchanged between cationic and anionic entities of differnet metal ions present in the complex.
(e) Ionization isomerism:
This type of isomerism arises when a counter ion replaces a ligand within the coordination sphere. Thus, complexes that have the same composition, but furnish different ions when dissolved in water are called ionization isomers. For e.g.,
(f) Solvate isomerism:
Solvate isomers differ by whether or not the solvent molecule is directly bonded to the metal ion or merely present as a free solvent molecule in the crystal lattice.
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